Wearable absorbent articles (e.g., taped diapers, pull-on diapers, training pants, sanitary napkins, panty liners, adult incontinence briefs, and bandages) typically offer the benefit of receiving and containing the bodily exudates of a wearer. Disposable varieties of such absorbent articles are commonly known, and can be made with various materials in a number of configurations. Such absorbent articles can include a chassis that defines a waist opening and a pair of leg openings, in addition to or further including side panels, and front or back ear panels.
Absorbent article materials may be made of numerous individual polymeric components that vary not only in terms of their properties, but also in their shape or form. They can be, for example, fibers, strands, fabrics, or films that can possess properties ranging from plastic to elastomeric. In order to produce stretch in materials, elastic materials can be combined while held under large strains with inelastic nonwovens (so called “live stretch”). These have been extensively used in the trade and appreciated for the textured appearance of the gathered nonwovens, but end up using large amounts of nonwoven, and thus may not be the most cost-effective route. An alternative to live stretch constructions are so called “zero-strain” constructions, where mechanical activation is used to apply large strains to a laminate that is comprised of an elastic layer and an inelastic nonwoven layer in order to permanently deform the inelastic layer of the laminate and enable the elastic layer to extend and retract.
In addition, large amounts of glue or adhesives are generally used in assembling the various components into a fully functional chassis. For example, in certain portions, adhesives may be used to attach a thin plastic film used as a fluid barrier to a nonwoven fabric that provides a cloth-like look and feel. Adhesives may be used in stretch elastic back ears or side panels where the adhesively-bonded nonwoven shields against the tacky or blocky nature of the elastic film onto the body side while again providing a soft fabric feel. Or adhesives may be used in the construction of legband or waistband laminates where live stretch strand elastics are sandwiched in between two layers of inelastic nonwovens that gather upon retraction.
One difficulty of working with adhesives is achieving the balance between the right level of adhesive to achieve adequate bond strength with cost while also preventing processing issues such as adhesive burn-through (pinholes) with thin films, adhesive bleed-through with nonwovens, or ruptures that can occur during activation due to the transfer of strain energy between the nonwoven and film. These issues can be difficult as it often requires the use of thicker or more complex nonwoven structures that can impose additional survivability issues during activation. Therefore, there is a continuing need for a way to maximize a laminate's extensibility through activation while still assuring survivability of the laminate.